In the Linux kernel, the following vulnerability has been resolved:
mm/vma: do not try to unmap a VMA if mmap_prepare() invoked from mmap()
The mmap_prepare hook functionality includes the ability to invoke
mmap_prepare() from the mmap() hook of existing 'stacked' drivers, that is
ones which are capable of calling the mmap hooks of other drivers/file
systems (e.g. overlayfs, shm).
As part of the mmap_prepare action functionality, we deal with errors by
unmapping the VMA should one arise. This works in the usual mmap_prepare
case, as we invoke this action at the last moment, when the VMA is
established in the maple tree.
However, the mmap() hook passes a not-fully-established VMA pointer to the
caller (which is the motivation behind the mmap_prepare() work), which is
detached.
So attempting to unmap a VMA in this state will be problematic, with the
most obvious symptom being a warning in vma_mark_detached(), because the
VMA is already detached.
It's also unncessary - the mmap() handler will clean up the VMA on error.
So to fix this issue, this patch propagates whether or not an mmap action
is being completed via the compatibility layer or directly.
If the former, then we do not attempt VMA cleanup, if the latter, then we
do.
This patch also updates the userland VMA tests to reflect the change.
mm/vma: do not try to unmap a VMA if mmap_prepare() invoked from mmap()
The mmap_prepare hook functionality includes the ability to invoke
mmap_prepare() from the mmap() hook of existing 'stacked' drivers, that is
ones which are capable of calling the mmap hooks of other drivers/file
systems (e.g. overlayfs, shm).
As part of the mmap_prepare action functionality, we deal with errors by
unmapping the VMA should one arise. This works in the usual mmap_prepare
case, as we invoke this action at the last moment, when the VMA is
established in the maple tree.
However, the mmap() hook passes a not-fully-established VMA pointer to the
caller (which is the motivation behind the mmap_prepare() work), which is
detached.
So attempting to unmap a VMA in this state will be problematic, with the
most obvious symptom being a warning in vma_mark_detached(), because the
VMA is already detached.
It's also unncessary - the mmap() handler will clean up the VMA on error.
So to fix this issue, this patch propagates whether or not an mmap action
is being completed via the compatibility layer or directly.
If the former, then we do not attempt VMA cleanup, if the latter, then we
do.
This patch also updates the userland VMA tests to reflect the change.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||
| Linux | Linux | affected |
|
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sun, 19 Jul 2026 10:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: mm/vma: do not try to unmap a VMA if mmap_prepare() invoked from mmap() The mmap_prepare hook functionality includes the ability to invoke mmap_prepare() from the mmap() hook of existing 'stacked' drivers, that is ones which are capable of calling the mmap hooks of other drivers/file systems (e.g. overlayfs, shm). As part of the mmap_prepare action functionality, we deal with errors by unmapping the VMA should one arise. This works in the usual mmap_prepare case, as we invoke this action at the last moment, when the VMA is established in the maple tree. However, the mmap() hook passes a not-fully-established VMA pointer to the caller (which is the motivation behind the mmap_prepare() work), which is detached. So attempting to unmap a VMA in this state will be problematic, with the most obvious symptom being a warning in vma_mark_detached(), because the VMA is already detached. It's also unncessary - the mmap() handler will clean up the VMA on error. So to fix this issue, this patch propagates whether or not an mmap action is being completed via the compatibility layer or directly. If the former, then we do not attempt VMA cleanup, if the latter, then we do. This patch also updates the userland VMA tests to reflect the change. | |
| Title | mm/vma: do not try to unmap a VMA if mmap_prepare() invoked from mmap() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-19T10:01:57.632Z
Reserved: 2026-06-09T07:44:35.401Z
Link: CVE-2026-53373
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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Weaknesses
No weakness.